Unit 2 Test: Kinematics (Dynamics)

Net Force

The total force acting on an object when all individual forces are combined; if it is zero, the object maintains constant velocity.

Constant Velocity

Motion at a fixed speed in a straight line without change in direction; occurs when net force is zero.

Newton's First Law

An object at rest remains at rest, and an object in motion continues at constant velocity unless acted upon by an external force.

Inertia

The tendency of an object to resist changes in its state of motion.

Newton's Second Law

The relationship stating that force equals mass times acceleration (F = ma).

Acceleration

The rate of change of velocity of an object, which may result from a change in speed or direction.

Friction

A force that opposes motion between two surfaces in contact.

Coefficient of Friction (Mu)

A unitless number that represents the frictional properties of the materials in contact.

Static Friction

The frictional force that prevents an object from starting to move until a certain threshold is exceeded.

F_fric

The force of friction, calculated as Ffric = M(Fnormal), where M is the coefficient of friction.

Normal Force (F_normal)

The support force exerted upon an object in contact with a stable surface, acting perpendicular to that surface.

Newton's Third Law

For every action, there is an equal and opposite reaction; forces always occur in pairs.

Action-Reaction Forces

The pair of forces exerted by two objects on each other; equal in magnitude and opposite in direction.

Dynamic Problem Solving Steps

1. Identify forces 2. Calculate net force 3. Use F = ma for missing forces 4. Solve using kinematic equations.

Kinematic Equations

Equations that relate the motion of an object under constant acceleration, including distance, velocity, acceleration, and time.

Balanced Forces

Forces that are equal in size but opposite in direction, resulting in no change in motion.

Unbalanced Forces

Forces that cause an object to accelerate, resulting in a change in its motion.

Proportional Relationship

A relationship where one quantity increases or decreases in direct relation to another, as seen between net force and acceleration.

Mass and Acceleration Relationship

The principle that heavier objects require more force to achieve the same acceleration as lighter objects.

Threshold of Static Friction

The maximum force that static friction can exert before an object begins to move.